Field measurements, assessments and improvement of Kang: Case study in rural northwest China

Many residents in northwest rural China use a traditional system of Kang to heat their houses during the winter. Kang as a simple and regionally cultural technique has been widely used in vast rural areas in northern China with a perpetual history. In fact, the current Kang system is inefficient and requires high levels of fuel consumption. Then, how to improve both the thermal performance and energy efficiency is of great importance to the construction and development of the new-type Kang. In this paper, the Kang widely used in northwest rural areas surrounding Xi'an of China has been taken as the test object. The tests were conducted in detail under different operating conditions of stoves (stove 1 and stove 2, separately or both combined). A series of evaluation indexes about Kang such as average surface temperature, standard deviation of surface temperature, instantaneous thermal efficiency, and indoor air temperature have been analyzed. An improved layout model for Kang flue has been developed to assist in designing and optimizing the domestic Kang heating system. Based on the numerical simulation, the improved layout model was demonstrated to lead to substantial improvement of Kang thermal environment characteristics. (C) 2015 Elsevier B.V. All rights reserved.